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2017-08-16x86/intel_rdt/cqm: Improve limbo list processingVikas Shivappa
During a mkdir, the entire limbo list is synchronously checked on each package for free RMIDs by sending IPIs. With a large number of RMIDs (SKL has 192) this creates a intolerable amount of work in IPIs. Replace the IPI based checking of the limbo list with asynchronous worker threads on each package which periodically scan the limbo list and move the RMIDs that have: llc_occupancy < threshold_occupancy on all packages to the free list. mkdir now returns -ENOSPC if the free list and the limbo list ere empty or returns -EBUSY if there are RMIDs on the limbo list and the free list is empty. Getting rid of the IPIs also simplifies the data structures and the serialization required for handling the lists. [ tglx: Rewrote changelog ... ] Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Link: http://lkml.kernel.org/r/1502845243-20454-3-git-send-email-vikas.shivappa@linux.intel.com
2017-08-16x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplugVikas Shivappa
When a CPU is dying, the overflow worker is canceled and rescheduled on a different CPU in the same domain. But if the timer is already about to expire this essentially doubles the interval which might result in a non detected overflow. Cancel the overflow worker and reschedule it immediately on a different CPU in same domain. The work could be flushed as well, but that would reschedule it on the same CPU. [ tglx: Rewrote changelog once again ] Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Link: http://lkml.kernel.org/r/1502845243-20454-2-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt: Show bitmask of shareable resource with other executing unitsFenghua Yu
CPUID.(EAX=0x10, ECX=res#):EBX[31:0] reports a bit mask for a resource. Each set bit within the length of the CBM indicates the corresponding unit of the resource allocation may be used by other entities in the platform (e.g. an integrated graphics engine or hardware units outside the processor core and have direct access to the resource). Each cleared bit within the length of the CBM indicates the corresponding allocation unit can be configured to implement a priority-based allocation scheme without interference with other hardware agents in the system. Bits outside the length of the CBM are reserved. More details on the bit mask are described in x86 Software Developer's Manual. The bitmask is shown in "info" directory for each resource. It's up to user to decide how to use the bitmask within a CBM in a partition to share or isolate a resource with other executing units. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: vikas.shivappa@linux.intel.com Link: http://lkml.kernel.org/r/20170725223904.12996-1-tony.luck@intel.com
2017-08-01x86/intel_rdt/mbm: Handle counter overflowVikas Shivappa
Set up a delayed work queue for each domain that will read all the MBM counters of active RMIDs once per second to make sure that they don't wrap around between reads from users. [Tony: Added the initializations for the work structure and completed the patch] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-29-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/mbm: Add mbm counter initializationVikas Shivappa
MBM counters are monotonically increasing counts representing the total memory bytes at a particular time. In order to calculate total_bytes for an rdtgroup, we store the value of the counter when we create an rdtgroup or when a new domain comes online. When the total_bytes(all memory controller bytes) or local_bytes(local memory controller bytes) file in "mon_data" is read it shows the total bytes for that rdtgroup since its creation. User can snapshot this at different time intervals to obtain bytes/second. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-28-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/mbm: Basic counting of MBM events (total and local)Tony Luck
Check CPUID bits for whether each of the MBM events is supported. Allocate space for each RMID for each counter in each domain to save previous MSR counter value and running total of data. Create files in each of the monitor directories. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-27-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add CPU hotplug supportVikas Shivappa
Resource groups have a per domain directory under "mon_data". Add or remove these directories as and when domains come online and go offline. Also update the per cpu rmids and cache upon onlining and offlining cpus. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-26-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add sched_in supportVikas Shivappa
OS associates an RMID/CLOSid to a task by writing the per CPU IA32_PQR_ASSOC MSR when a task is scheduled in. The sched_in code will stay as no-op unless we are running on Intel SKU which supports either resource control or monitoring and we also enable them by mounting the resctrl fs. The per cpu CLOSid/RMID values are cached and the write is performed only when a task with a different CLOSid/RMID is scheduled in. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-25-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add mount,umount supportVikas Shivappa
Add monitoring support during mount and unmount. Since root directory is a "ctrl_mon" directory which can control and monitor resources create the "mon_groups" directory which can hold monitor groups and a "mon_data" directory which would hold all monitoring data like the rest of resource groups. The mount succeeds if either of monitoring or control/allocation is enabled. If only monitoring is enabled user can still create monitor groups under the "/sys/fs/resctrl/mon_groups/" and any mkdir under root would fail. If only control/allocation is enabled all of the monitoring related directories/files would not exist and resctrl would work in legacy mode. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-23-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add mon_dataVikas Shivappa
Add a mon_data directory for the root rdtgroup and all other rdtgroups. The directory holds all of the monitored data for all domains and events of all resources being monitored. The mon_data itself has a list of directories in the format mon_<domain_name>_<domain_id>. Each of these subdirectories contain one file per event in the mode "0444". Reading the file displays a snapshot of the monitored data for the event the file represents. For ex, on a 2 socket Broadwell with llc_occupancy being monitored the mon_data contents look as below: $ ls /sys/fs/resctrl/p1/mon_data/ mon_L3_00 mon_L3_01 Each domain directory has one file per event: $ ls /sys/fs/resctrl/p1/mon_data/mon_L3_00/ llc_occupancy To read current llc_occupancy of ctrl_mon group p1 $ cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy 33789096 [This patch idea is based on Tony's sample patches to organise data in a per domain directory and have one file per event (and use the fp->priv to store mon data bits)] Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-20-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt: Prepare to add RDT monitor cpus file supportVikas Shivappa
Separate the ctrl cpus file handling from the generic cpus file handling and convert the per cpu closid from u32 to a struct which will be used later to add rmid to the same struct. Also cleanup some name space. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-17-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt: Change closid type from int to u32Vikas Shivappa
OS associates a CLOSid(Class of service id) to a task by writing the high 32 bits of per CPU IA32_PQR_ASSOC MSR when a task is scheduled in. CPUID.(EAX=10H, ECX=1):EDX[15:0] enumerates the max CLOSID supported and it is zero indexed. Hence change the type to u32 from int. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-15-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add mkdir support for RDT monitoringVikas Shivappa
Resource control groups can be created using mkdir in resctrl fs(rdtgroup). In order to extend the resctrl interface to support monitoring the control groups, extend the current mkdir to support resource monitoring also. This allows the rdtgroup created under the root directory to be able to both control and monitor resources (ctrl_mon group). The ctrl_mon groups are associated with one CLOSID like the legacy rdtgroups and one RMID(Resource monitoring ID) as well. Hardware uses RMID to track the resource usage. Once either of the CLOSID or RMID are exhausted, the mkdir fails with -ENOSPC. If there are RMIDs in limbo list but not free an -EBUSY is returned. User can also monitor a subset of the ctrl_mon rdtgroup's tasks/cpus using the monitor groups. The monitor groups are created using mkdir under the "mon_groups" directory in every ctrl_mon group. [Merged Tony's code: Removed a lot of common mkdir code, a fix to handling of the list of the child rdtgroups and some cleanups in list traversal. Also the changes to have similar alloc and free for CLOS/RMID and return -EBUSY when RMIDs are in limbo and not free] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-14-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add info files for RDT monitoringVikas Shivappa
Add info directory files specific to RDT monitoring. num_rmids: The number of RMIDs which are valid for the resource. mon_features: Lists the monitoring events if monitoring is enabled for the resource. max_threshold_occupancy: This is specific to llc_occupancy monitoring and is used to determine if an RMID can be reused. Provides an upper bound on the threshold and is shown to the user in bytes though the internal value will be rounded to the scaling factor supported by the h/w. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-12-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt: Simplify info and base file listsTony luck
The info directory files and base files need to be different for each resource like cache and Memory bandwidth. With in each resource, the files would be further different for monitoring and ctrl. This leads to a lot of different static array declarations given that we are adding resctrl monitoring. Simplify this to one common list of files and then declare a set of flags to choose the files based on the resource, whether it is info or base and if it is control type file. This is as a preparation to include monitoring based info and base files. No functional change. [Vikas: Extended the flags to have few bits per category like resource, info/base etc] Signed-off-by: Tony luck <tony.luck@intel.com> Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-11-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add RMID (Resource monitoring ID) managementVikas Shivappa
Hardware uses RMID(Resource monitoring ID) to keep track of each of the RDT events associated with tasks. The number of RMIDs is dependent on the SKU and is enumerated via CPUID. We add support to manage the RMIDs which include managing the RMID allocation and reading LLC occupancy for an RMID. RMID allocation is managed by keeping a free list which is initialized to all available RMIDs except for RMID 0 which is always reserved for root group. RMIDs goto a limbo list once they are freed since the RMIDs are still tagged to cache lines of the tasks which were using them - thereby still having some occupancy. They continue to be in limbo list until the occupancy < threshold_occupancy. The threshold_occupancy is a user configurable value. OS uses IA32_QM_CTR MSR to read the occupancy associated with an RMID after programming the IA32_EVENTSEL MSR with the RMID. [Tony: Improved limbo search] Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-10-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt/cqm: Add RDT monitoring initializationVikas Shivappa
Add common data structures for RDT resource monitoring and perform RDT monitoring related data structure initializations which include setting up the RMID(Resource monitoring ID) lists and event list which the resource supports. [ tony: some cleanup to make adding MBM easier later, remove "cqm" from some names, make some data structure local to intel_rdt_monitor.c static. Add copyright header] [ tglx: Made it readable ] Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-9-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt: Cleanup namespace to support RDT monitoringVikas Shivappa
Few of the data-structures have generic names although they are RDT allocation specific. Rename them to be allocation specific to accommodate RDT monitoring. E.g. s/enabled/alloc_enabled/ No functional change. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-7-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01x86/intel_rdt: Change file names to accommodate RDT monitor codeVikas Shivappa
Because the "perf cqm" and resctrl code were separately added and indivdually configurable, there seem to be separate context switch code and also things on global .h which are not really needed. Move only the scheduling specific code and definitions to <asm/intel_rdt_sched.h> and the put all the other declarations to a local intel_rdt.h. h/t to Reinette Chatre for pointing out that we should separate the public interfaces used by other parts of the kernel from private objects shared between the various files comprising RDT. No functional change. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-5-git-send-email-vikas.shivappa@linux.intel.com